Investigation on the correlation between the structure of azulen-1-yl-benzothiazol-2-yl diazenes and their properties. Acidity and electrochemical redox potentials

Acidity and redox potentials of a series of substituted azulen-1-yl-benzothiazol-2-yl diazenes are correlated with several theoretical parameters. From the electronic spectra of the dyes recorded at different pH, the derived pKa values correlate well with para Hammett-constants. The experimental oxidation and reduction potentials, as determined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), are in good agreement with the calculated frontier orbital energies, for the studied dyes.